Project description:The aim of this project is to deeply map the proteome of mitochondria from the model plant Arabidopsis thaliana. For this purpose, mitochondria were isolated from Arabidopsis cell cultures, their proteins extracted and processed using SP3 digestion. To achieve high sequence coverage, the proteins were digested with a total of six different proteases and measured using sensitive timsTOF Pro hardware and TIMS fractionation.
Project description:Protein phosphorylation and ubiquitination are two of the most abundant forms of post-translational modifications in eukaryotes, regulated by thousands of protein kinases, phosphatases, E3 ubiquitin ligases, and ubiquitin proteases. Although previous studies have catalogued several ubiquitinated proteins in plants (Walton et al., 2016), few membrane-localized proteins have been identified. Receptor kinases (RKs) initiate phosphorylation signal relays that regulate plant growth, development, and stress responses. While the regulatory role of phosphorylation on protein kinase function is well-documented (Couto and Zipfel, 2016), considerably less is known about the role of ubiquitination on protein kinase function, even though protein turnover is critical to their signaling competence and cellular homeostasis. Here we describe the large-scale identification of ubiquitination sites on Arabidopsis proteins associated with or integral to the plasma membrane, including over 100 protein kinases.
